/* semlib.h */
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>

#define DELAY_TIME 2

union semun {
    int val;
    struct semid_ds *buf;
    unsigned short *array;
};

int init_sem(int sem_id, int init_value);
int del_sem(int sem_id);
int sem_p(int sem_id);
int sem_v(int sem_id);
